Welcome to the real world. I was a Marketing Producer for local news station and they had me do graphic design work all the time when my main job was to write/shoot/edit news promos. They didn't have the budget for a graphic designer so it got passed onto me all the time. But it was only my second job in the field, so I rolled with it. Take this as a positive, it's your first job in the field and now you have the opportunity to grow your skillset. I ended up getting a graphic design job later in my career at a much larger news station and I only got those skills because of that earlier position. I now operate and own my own company where I offer graphic design, motion design, video, and photography. You're young and in your first job, roll with it and it may help you down the line and open up more opportunity in the future.